


You've Got a Secret, I Guess (Older Than You Look)

by aktura



Category: Shadowhunters (TV)
Genre: (actually fight Alec he has done the math), Attempt at Humor, Domestic Magnus Bane/Alec Lightwood, M/M, Magnus did not have 17000 lovers (fight me), Magnus likes to tease Alec (Alec loves it), They are happy and in love, playful husbands
Language: English
Status: Completed
Published: 2020-04-11
Updated: 2020-04-11
Packaged: 2021-03-01 22:07:17
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,954
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23594314
Author URL: https://archiveofourown.org/users/aktura/pseuds/aktura
Summary: “Guess,” Magnus says.Alec huffs a laugh, rinsing one of the plates and putting it aside to be dried. “Guess? You’re seriously not gonna tell me?”Magnus taps the rim of the martini glass against his bottom lip, looking thoughtful. “No, I don't think so. You should guess.”In which Magnus won't tell Alec how old he is.
Relationships: Magnus Bane/Alec Lightwood
Comments: 38
Kudos: 269





	You've Got a Secret, I Guess (Older Than You Look)

**Author's Note:**

> This is a silly piece, but I had a lot of fun writing it. Hope you enjoy!
> 
> Title from _Dive_ by Cloud.

–––– o ––––

Much to Alec’s dismay, Magnus won’t tell him.

“It lends to my air of mystery,” his husband says with a grandiose yet graceful sweep of his arm, and fuck, Alec loves this ridiculous man. 

Still—

“We’re married,” Alec points out, reaching across the table to grab Magnus’ plate so that he can pile it onto his own and carry both dishes into the kitchen.

“So?” Magnus sashays after him, draping himself across Alec’s back and embracing him from behind where he’s standing by the sink. Pushing himself up on his tiptoes, he hooks his chin over Alec’s shoulder to watch Alec prepare for the clean up. “You know I could—”

“I like it,” Alec cuts him off, turning the faucet off and dipping his hands into the rising soap suds. “It’s relaxing. Like showers, right?”

“Darling, _no_ ,” Magnus disagrees, but doesn’t repeat his offer of magical assistance.

“Point is,” Alec says, “we’re married; you don’t need to keep up an air of mystery around me. I mean, last night you slept on my chest and then spent most of breakfast picking hair out of your teeth.” Magnus gives an undignified snort against Alec’s shoulder. “So why won’t you tell me how old you are?”

“Next you’re going to want to know my birth name,” Magnus murmurs, breath tickling the skin below Alec’s ear, and Alec can’t help but shiver.

“Baby steps,” he replies, which makes Magnus laugh; Alec can feel the vibrations rumble through Magnus’ chest where he’s pressed up against Alec’s back. “So, are you gonna tell me?”

Magnus hums, fingers playing with the top buttons of Alec’s shirt, sneaking in between to pet at his chest. “No, I don’t think so,” he says, pulling away and padding out of the kitchen.

“Magnus—” 

Alec’s feeling a bit cold now that Magnus is no longer pressed up against him. He can hear the rattle of glass in the living room as Magnus pours himself a martini, and soon enough his husband is back in the kitchen, gracefully hopping onto the kitchen counter next to the sink and crossing his legs with a flourish. He takes a sip of his drink, eying Alec over the rim of the glass, and Alec’s struck by how stunningly beautiful Magnus is like this – relaxed, playful, and all Alec’s.

“Guess,” Magnus says.

Alec huffs a laugh, rinsing one of the plates and putting it aside to be dried. “Guess? You’re seriously not gonna tell me?”

Magnus taps the rim of the martini glass against his bottom lip, looking thoughtful. “No, I don’t think so. You should guess.”

“Fine,” Alec says, smiling, and doesn’t protest when Magnus vanishes the clean plate with a flick of his wrist – he’s never liked the drying part much anyway. “I will.”

“But only one guess per day,” Magnus tells him. “Can’t make it too easy for you, my clever little Inquisitor.”

Alec sets the second plate aside and drains the dirty water from the sink, and then reaches out to touch the side of Magnus’ neck, feeling his husband shiver as the water from Alec’s fingers drips down to escape under his collar.

“Starting now?” Alec asks, leaning over to brush his lips against Magnus’, and when Magnus hums he says, “Alright. I’ll start off with 400.”

Magnus nips at Alec’s bottom lip. “Wrong.”

“That’s too bad,” Alec says. His hand comes to rest on Magnus’ thigh, and when Magnus uncrosses his legs, reaching out to tug at Alec’s shirt, Alec doesn’t hesitate to press closer.

–––– o ––––

“Huh,” Alec says.

“Hmm?” Magnus looks up from the burbling mixture brewing in his cauldron to find Alec leaning against the door jam to his potions room, seemingly fully engrossed in a copy of _Smithsonian Magazine_. “Darling, where did you find that? It’s from 2005.” Magnus raises his hand. “Let me get you a more recent edition.”

“No, look— Know how you really like telling people that thing about the Dead Sea?”

“It _is_ a good one,” Magnus agrees.

“Well, listen to this: ‘Originally part of an ancient, much larger lake that extended to the Sea of Galilee, its outlet to the sea evaporated some 18,000 years ago, leaving a salty residue in a desert basin at the lowest point on earth’.” Alec levels him a flat look. “This whole time, you’ve been walking around telling people you’re _eighteen thousand years old?_ ”

“In my defense,” Magnus says, “none of them have ever caught on.”

“Magnus—”

“Was that your guess?”

Alec blinks. “My guess— What? No. You’re not _that_ old.”

“You’re absolutely right, darling,” Magnus agrees. “Ugh, could you _imagine?_ ” He shudders in a exaggerated manner. “Better luck tomorrow, then!”

“That wasn’t a— _Magnus!_ ”

–––– o ––––

“So,” Alec says as Magnus lazily cards his fingers through his chest hair, “I did some math.”

“Oh, _Alexander_ ,” Magnus purrs. “I love your pillow talk.”

Alec huffs. “Shut up,” he says, using the hand that’s still cupping Magnus’ ass to give his husband a pinch. Magnus breathes a laugh against Alec’s shoulder, flicking one of his nipples in retaliation. “Ow— stop that.”

“You were saying?” Magnus nuzzles against Alec’s chest, placing a kiss to the nipple he so viciously abused. “You did some math?”

“Yeah.” Alec’s breath hitches as Magnus’ fingers start petting their way down his chest. “I, uh— So, you’re a one soul at a time kind of person, and I know about some of the, uh, people you’ve been with—” He’s careful not to bring up the likes of Camille in the afterglow – or, judging by the way Magnus just hitched his leg up to press closer against Alec’s side and the direction his clever fingers are heading, the start of round two. “—and I know that some of them have probably been a one time thing, but 17,000 lovers seem like a lot of people.”

Magnus stops tracing his fingertips over the skin of Alec’s hip bone – something Alec feels really sorry about – and props his chin up on Alec’s stomach, peering up at him. _Go on_ , his eyes seem to say, so Alec does.

“Even if 10,000 of them were one night stands and 5,000 only lasted one month, you’d still have to be almost 2,000 years old to have time for both them and the long term relationships. And that’s if you were never single. So if you were single, like, twenty five percent of the time, that would make you around 2,500 years old.”

Magnus blinks. “You’ve put a lot of thought into this,” he says, voice giving away nothing.

Alec shrugs, feeling kind of embarrassed all of a sudden.

“So what is your conclusion, oh brilliant husband of mine?” Magnus asks.

Alec clears his throat. “Either you’re at least 2,500 years old, or you lied about the number.”

Magnus smiles, pushing himself up so that he’s face to face with Alec again.

“Are you? 2,500 years old, I mean.”

“No, love,” Magnus murmurs, dipping down to give Alec a kiss.

“That’s— good,” Alec manages, breath hitching as Magnus tugs the covers off him. “Wow, that really got you doing. Was it the math?”

Magnus laughs, pulling back to press a kiss to Alec’s nose, and then to his right cheek, followed by his forehead. “No, darling. That was all you.”

–––– o ––––

Alec frowns and looks up from his tablet.

“You’re not old enough to have known Michelangelo,” he decides.

Magnus smirks at him from the other end of the couch. “Are you fishing for clues, Alexander? Trying to figure out my tells?”

“I already know your tells,” Alec retorts dryly. 

Magnus stretches a leg out to poke at Alec’s thigh with his toes. “So guess, then.”

Alec squints at him, a considering look on his face. “You probably wouldn’t have slept with an old man, so if Michelangelo was born in 1475—”

“Are you on Wikipedia?” Magnus asks, leaning over to try to catch a look at the screen of Alec’s tablet.

“—then let’s say 1525 at the latest,” Alec continues. “So, how about 652?”

“That would be wrong,” Magnus says cheerfully. He gives Alec another poke with his toes and then quickly pulls his foot back before Alec has a chance to grab it.

–––– o ––––

“656?”

“No, darling.”

–––– o ––––

“675?”

“Wrong again,” Magnus says as he spreads a thick layer of marmalade on his toast. “Maybe,” he drawls, “I preferred— how was it you put it? ‘Old man Michelangelo’.”

Alec sets down his coffee cup. “Seriously?”

Magnus takes a bite of his toast.

–––– o ––––

“Magnus?”

Magnus groans, slapping at Alec’s hand, but Alec isn’t deterred.

“Magnus!” he hisses, giving his husband another shake. “I forgot to guess today. Is it 267?”

Magnus rolls over, dislodging Alec’s hand from his shoulder. He flops onto Alec’s chest, burrowing his face into the side of Alec’s neck and sighs, breath ghosting warm across Alec’s skin. “What time izzit?” he murmurs.

“It’s almost midnight,” Alec whispers, trailing his fingers down the long line of Magnus’ spine.

“Nuh,” Magnus sighs.

Alec blinks. “Does that mean I was wrong?”

“Nuh,” Magnus says again, sleepily patting at Alec’s side and Alec can’t take that as anything but an affirmative. 

“Alright,” he whispers, pressing a kiss to Magnus’ temple. “Go back to sleep, okay?”

Magnus is already way ahead of him.

–––– o ––––

When Izzy’s birthday rolls around, Magnus whisks her away for a shopping spree in Milan, a treat courtesy of the Lightwood-Banes. 

For a moment Alec is afraid that he might be invited to tag along, but Izzy thankfully bans him from coming, loudly declaring that his long reach might bless him with the ability to carry many bags at once, but it does not make up for the long-suffering sighs, the eye rolls, or the not-at-all-funny comments he tends to start dropping after the fifth store.

Relieved, Alec gives his sister a hug, kisses his husband goodbye, and then spends the day on the balcony, reading _The Count of Monte Cristo_ , until about five o’clock when a portal opens up in the living room and a dozen or so bags come tumbling through to pile up on the hardwood floor. Magnus follows soon after, gracefully stepping over the small mountain that preceded him, and Alec makes sure his bookmark is tucked into place before he rises to greet his husband.

“I portaled Isabelle to the Institute first,” Magnus tells him, as if to clarify that he didn’t abandon Izzy in Italy, and Alec smiles fondly and gives him a kiss on the cheek.

“Show me what you got,” Alec prompts and settles down on the couch.

It isn’t something that Alec ever thought he’d enjoy, to be honest, but he has to admit that there’s pleasure to be found in watching his husband show off his new clothes. Magnus loves it too; he always lights up at the opportunity to dress up and seems to bask in pleasure at having Alec’s full attention on him, and today is no exception.

“This one was rather pricey,” he says, running his hands down the front of the fitted blue coat, “but I do rather like the detailing on the back, don’t you? And it does flatter my shoulders.”

To Alec, the coat looks the same as the previous three, but he nods anyway. “You don’t look a day over 700.”

Magnus glances at him out of the corner of his eye. “I don’t know if I should take that as a compliment or an insult.”

“Depends on if you’re older than 700 or not.”

Magnus looks delighted at Alec’s subterfuge. “How dastardly!” he says, “I’ve taught you well, Shadowhunter. Sadly, you are wrong yet again.”

He leaves it at that, neither confirming nor denying that he’s older than 700, but he gives Alec a kiss for effort, so Alec can’t really complain.

–––– o ––––

“Wait, hang on— Magnus?”

Magnus pokes his head out of the bathroom to find Alec in bed, leaning against the headboard and frowning down at his tablet.

“Are you on Wikipedia again, darling?”

“Yes, but— When you said that you spent the night with Casanova at the Doge’s Palace— You said he was your _roommate_ —”

Magnus grins and steps out of the bathroom, running a towel through his hair. “Are you asking me if I’ve been to prison, Alexander? If I too have been arrested for affront to religion and common decency?”

“Magnus, I swear to god—”

“They put him in solitary confinement at first, if I recall correctly,” Magnus says, vanishing the towel back into the bathroom. “There was a prison on the top floor of the east wing of the Doge's Palace. The Leads, it was called, because of the lead plates covering the roof. Very unpleasant in summertime, or so I’ve heard.”

Alec squints at him. “He had cellmates,” he says.

Magnus hums as he crawls into bed and slips beneath the covers. “Yes, eventually.”

“Cellmates are like roommates.”

Magnus reaches out to pluck the tablet out of Alec’s hands. “Darling, a _mundane_ prison? It wouldn’t hold me for long.”

“Which is why you only spent one night together.”

“Allegedly,” Magnus says. “Though I guess it would be difficult to portal one’s way out without arousing attention if locked in a cell with four other men.”

“ _Four_ other— Wait, you didn’t invent the portal until 1878. This was more than a hundred years before that.”

“Which is why this is all _alleged_ , my dear Alexander.”

Alec sighs, but lets Magnus pull him down so that they’re both on their sides, sharing a pillow. “So if I guessed 292, that wouldn’t be right?”

“No, I’m afraid not.” Magnus trails his fingers down the side of Alec’s neck, petting at his chest. “But why waste time talking about Casanova when I have an Adonis in my bed?”

Alec flushes, and when Magnus rolls onto his back and tugs Alec on top of him, Alec goes eagerly. 

–––– o ––––

“I was looking over the Clave’s case files today,” Alec says casually, cutting into his steak, “and I came across yours, which got me thinking.”

Magnus smirks at him from across the table. “Oh, _Alexander_. Looking at pictures of me at work again?”

“So your file says that you were born in Batavia, right?” Alec continues, ignoring both Magnus and the heat he can feel rising in his cheeks at his husband’s innuendo. “I looked it up, and while that area of the Dutch East Indies was settled by the Dutch in the early 1600s, Batavia wasn’t officially named such until 1621.”

Magnus hums thoughtfully as he plops another piece of steak in his mouth and starts chewing. 

“Which means,” Alec forges on, “that you can’t have been born earlier than that. Which makes you no older than 397, at most.”

Magnus swallows. “Ah yes, the Clave’s files,” he drawls, looking up and to the left as if reminiscing. “They say so much, little of which can be trusted as fact. If I’m not mistaken, they also state that I’m 5’11” when I’m clearly _much_ taller.”

“Clearly,” Alec says. And then, “So?”

“So, am I 397 years old?” Magnus flutters his eyelashes at his husband before cutting into his steak again. “No.”

“Dammit.”

“Look on the bright side, darling. Just think of the wealth of knowledge you have acquired about world history,” Magnus says. “How much richer is not your life right now for having learned so much about the affairs of the Dutch during the 17th century?”

Alec sighs. “Just pass me the wine, please?”

–––– o ––––

Alec likes to walk to his office in the mornings. It might be more convenient to have Magnus open a portal, but there’s something to be said about doing it the old fashioned way. Besides, Alec finds it important to spend time in the streets of the city – both to keep in touch with the people of Alicante, but also to let them see that as High Inquisitor, Alec won’t be spending all his time up in his ivory tower in the Gard.

This morning, however, Alec is running late.

It’s his own doing, to be honest – he’d woken up at dawn and leaned over to give Magnus a kiss good morning, and then hadn’t wanted to stop, so he didn’t. He’d ended up pressing a laughing Magnus down into the mattress, and had used his hands and mouth to make his husband fall apart, giggles turned into moans, followed by an afterglow that had left them both trembling. 

Magnus still looks disheveled even now, hair in disarray and unglamored cat eyes peering at Alec from beneath heavy lids as he opens the portal that will take Alec from their bedroom straight to his office. Alec knows Magnus could make himself look presentable with a snap of his fingers – and he will, once Alec’s left and time comes to welcome clients into their home – but for the moment he stays rumpled simply because he knows that Alec likes to see him like this, likes to see his handiwork on display as Magnus lounges around the apartment, looking well-fucked and sleep-warm, comfortable in his almost-sheer night robe.

Magnus shoots him a sultry look as Alec buttons the last button on his shirt, and lifts his chin in expectation of a kiss. Alec obliges him, stepping closer and leaning down to kiss him, shallow and sweet, swallowing Magnus’ contented sigh.

“Hmm,” Alec murmurs against Magnus’ lips. “Eighty seven.”

Magnus places a hand on Alec’s chest, pushing him back. “Alexander!” he gasps, his eyebrows raised, and he sounds absolutely scandalized.

Alec laughs and leans down to steal another kiss, feeling Magnus playfully pinch his side in retaliation. 

He’s still laughing as he steps through the portal.

–––– o ––––

**Author's Note:**

> The Smithsonian article is an actual thing and can be found [here](https://www.smithsonianmag.com/science-nature/the-dying-of-the-dead-sea-70079351/), as was Casanova’s imprisonment in (and later escape from) the prison in the Doge’s Palace, which you can read more about [here](https://en.wikipedia.org/wiki/Giacomo_Casanova#Imprisonment_and_escape).


End file.
